Scanning shows that the amphibian, which was suffering from broken ribs, crawled into a sleeping mammal’s shelter for protection.

Some would call Thrinaxodon a mammal-like reptile, not a real mammal yet.

This research suggests that short periods of dormancy, called aestivation, in addition to burrowing behaviour, may have been a crucial adaptation that allowed mammal ancestors to survive the extinction.

The results of this research resulted in a paper entitled Synchrotron reveals Early Triassic odd couple: injured amphibian and aestivating therapsid share burrow and that is published in a scientific journal. Kristian Carlson, from the South Africa Universities of Witts, denied that the evidence shows that they were feeding on each other, even when one of them had broken ribs.

The use of communal latrines has only been known for some recent mammals, such as horses, tapirs, and elephants, and for some birds such as the ancient, ostrich-like Moa. The new findings show that the complex behavior was also present in distant relatives of mammals, the rhino-like reptiles called dicynodonts, dating to a time much older than previously suspected: here.